If you actually look at this, the results are not nearly as bad as title suggests. There are are many parsers which perfectly parse every valid JSON document (

If you actually look at this, the results are not nearly as bad as title suggests. There are are many parsers which perfectly parse every valid JSON document (like every Perl, Python and PHP parser and many others). They got non-perfect score because they accepted some JSON which standard says they should not have -- like a NaN value or a trailing comma. While using such parsers can potentially cause problems -- perhaps because your data generator has a bug, and your not-strict-enough parser ignores this bug -- this happens very rarely in practice.